Recently, non-contact electric power transmission comes to be widely used. A communication device having a non-contact electric power transmission function receives electric power, which is transmitted to an antenna (antenna section) via an electromagnetic wave, with use of electromagnetic induction. The communication device also makes communication with an external device via the antenna. For example, a communication device having a Near field communication (NFC) function makes communication via the electromagnetic wave with use of a RFID provided with a loop antenna. In general, the electric power generated due to the electromagnetic induction in the non-contact electric power transmission is rather larger than the electric power generated due to the electromagnetic induction in the communication such as the NFC. Accordingly, when the communication device carries out the non-contact electric power transmission, a communication section of the communication device might receive excessive electric power larger than its endurable voltage. As a result, the communication section might be damaged.
Patent Document 1 discloses a communication device having the communication function and the non-contact electric power transmission function. The communication device of Patent Document 1 comprises an antenna, a communication section, a switch control section and a switch circuit. The switch circuit is provided between the antenna and the communication section. The switch control section controls ON/OFF of the switch circuit depending on the electric power which the antenna receives. This control protects the communication section against large electric power.